题目链接:
abs
Time Limit: 2000/1000 MS (Java/Others)
Memory Limit: 131072/131072 K (Java/Others)
Problem Description
Given a number x, ask positive integer y≥2, that satisfy the following conditions:
1. The absolute value of y - x is minimal
2. To prime factors decomposition of Y, every element factor appears two times exactly.
Input
The first line of input is an integer T ( 1≤T≤50)
For each test case,the single line contains, an integer x ( 1≤x≤1018)
Output
For each testcase print the absolute value of y - x
Sample Input
5
1112
4290
8716
9957
9095
Sample Output
23
65
67
244
70
题意:
给一个x,然后让你找一个y,分解质因子后y的质因子次幂均为2,使abs(y-x)最小;
思路:
枚举x周围的那些数,看是否符合条件然后更新答案就好了;
AC代码:
/************************************************ ┆ ┏┓ ┏┓ ┆ ┆┏┛┻━━━┛┻┓ ┆ ┆┃ ┃ ┆ ┆┃ ━ ┃ ┆ ┆┃ ┳┛ ┗┳ ┃ ┆ ┆┃ ┃ ┆ ┆┃ ┻ ┃ ┆ ┆┗━┓ ┏━┛ ┆ ┆ ┃ ┃ ┆ ┆ ┃ ┗━━━┓ ┆ ┆ ┃ AC代马 ┣┓┆ ┆ ┃ ┏┛┆ ┆ ┗┓┓┏━┳┓┏┛ ┆ ┆ ┃┫┫ ┃┫┫ ┆ ┆ ┗┻┛ ┗┻┛ ┆ ************************************************ */ #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <cmath> #include <bits/stdc++.h> #include <stack> using namespace std; #define For(i,j,n) for(int i=j;i<=n;i++) #define mst(ss,b) memset(ss,b,sizeof(ss)); typedef long long LL; template<class T> void read(T&num) { char CH; bool F=false; for(CH=getchar();CH<‘0‘||CH>‘9‘;F= CH==‘-‘,CH=getchar()); for(num=0;CH>=‘0‘&&CH<=‘9‘;num=num*10+CH-‘0‘,CH=getchar()); F && (num=-num); } int stk[70], tp; template<class T> inline void print(T p) { if(!p) { puts("0"); return; } while(p) stk[++ tp] = p%10, p/=10; while(tp) putchar(stk[tp--] + ‘0‘); putchar(‘\n‘); } const LL mod=1e9+7; const double PI=acos(-1.0); const LL inf=1e18; const int N=1e5+10; const int maxn=1e5+4; const double eps=1e-8; int cnt,vis[N],prime[N]; inline void Init() { cnt=0; For(i,2,maxn) { if(!vis[i]) { for(int j=2*i;j<maxn;j+=i) vis[j]=1; prime[++cnt]=i; } } } inline int check(LL x) { for(int i=1;i<=cnt;i++) { if(x<prime[i])break; if(x%prime[i]==0) { x=x/prime[i]; if(x%prime[i]==0)return 0; } } return 1; } int main() { int t; read(t); Init(); while(t--) { LL n; read(n); LL temp=sqrt(n+0.5),ans=inf; int flag=0; for(LL i=0; ;i++) { if(check(temp+i)&&(temp+i)*(temp+i)>=2){ans=min(ans,abs((temp+i)*(temp+i)-n));flag=1;} if(check(temp-i)&&temp>i&&(temp-i)*(temp-i)>=2)ans=min(ans,abs((temp-i)*(temp-i)-n)),flag=1; if(flag&&i>=6)break; } cout<<ans<<"\n"; } return 0; }
时间: 2024-10-10 16:32:21